Thirty-one RCTs (n=2,079) were included. The authors were unable to obtain one potentially eligible study.
Ten RCTs scored 3 or more points out of 5 on the Jadad scale. Seven studies used intention-to-treat analysis. Two RCTs reported a power calculation. Methodological flaws included small sample sizes and inadequate descriptions of methods, population characteristics, wounds and results.
Leg ulcers of venous origin (26 studies).
Modern versus conventional dressings.
Efficacy: there was no statistically significant difference in the proportion of ulcers healed between hydrocolloid dressings and conventional dressings (RR 0.90, 95% CI: 0.85, 1.15, P=0.9), based on 8 studies (n=782). There was no statistically significant difference in the proportion of ulcers healed between conventional dressings and any of the following modern dressings: polyurethane dressings (3 studies), alginate (2 studies), collagen (1 study), or activated charcoal (1 study).
Withdrawals: there was no statistically significant difference in withdrawal rates between modern and conventional dressings (RR 1.20, 95% CI: 0.76, 1.89, P=0.4), based on 12 studies (n=955).
Modern dressings versus each other.
Efficacy: there was no statistically significant difference in the proportion of ulcers healed between hydrocolloid dressings and other modern dressings (RR 1.13, 95% CI: 0.86, 1.47, P=0.4), based on 6 studies (n=319).
Withdrawals: withdrawal rates varied amongst the studies. There was no statistically significant difference in withdrawal rates between intervention and comparator groups (RR 0.75, 95% CI: 0.41, 1.37, P=0.4), based on 5 studies.
Safety: there was no statistically significant difference in adverse effects between modern and conventional treatments (RR 1.20, 95% CI: 0.75, 1.96, P=0.4). The most common adverse effects for studies comparing modern versus conventional dressings were clinical deterioration of the wound and signs of local infection with or without cellulitis. The reviewers mentioned hypersensitivity and allergic reactions with modern dressings, but gave no further details. For studies comparing different types of modern dressings, there was no statistically significant difference in adverse effects between treatment and comparator groups (RR 0.79, 95% CI: 0.37, 1.67, P=0.5).
Leg ulcers of mixed or undifferentiated origin (5 studies).
Efficacy: there was no statistically significant difference in the rate of healing of mixed ulcers between polyurethane versus gauze-saline (1 study), or between hydrocolloid versus either gauze-saline (1 study), alginate (1 study) or occlusive zinc (1 study).
Withdrawals: the number of patients withdrawing was similar for both treatment groups in 3 studies (1 patient in each group for conventional versus modern dressings, 5 with hydrocolloid versus 7 with alginate in the second study, and 6 each for hydrocolloid and zinc dressings in the third study).
Safety: there was one case of erysipelas with moist gauze (1 study), and 6 adverse reactions with hydrocolloid versus 4 with zinc (1 study).